Superplastic Flow of Metals Extruded by KoBo Method

Article Preview

Abstract:

The extrusion of metals by the KoBo method, which is a new technological solution, allows to perform the process at low temperature with severe plastic deformation (SPD) under cyclic change of deformation path conditions. Apart from the localized plastic flow in shear bands intensive generation of point defects (self interstitials) takes place. It is important that excessive concentration of interstitial atoms is preserved in extruded products and often takes the shape of nanoclusters. Their presence causes that the effect of superplasticity (e.g. about 800% elongation of aluminum alloy 7075) does not require nanometric sizes of the grains and appears in metals extruded by the KoBo method with grains of over dozen or even several dozen micrometers. The results suggest the necessity to verify the mechanisms currently considered as decisive of the superplastic flow of metals.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 667-669)

Pages:

1039-1044

Citation:

Online since:

December 2010

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2011 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] A. Korbel, W. Bochniak, European Patent No0711210, U.S. Patent No573959.

Google Scholar

[2] W. Bochniak, K. Marszowski, A. Korbel, J. Mater. Proc. Technol. 169 (2005), p.44.

Google Scholar

[3] W. Bochniak, A. Korbel, Mater. Sci. Technol. 16 (2000), p.664.

Google Scholar

[4] A. Korbel, W. Bochniak, P. Ostachowski, L. Błaż, Visco-plastic flow of metal in dynamic conditions of complex strain scheme, submitted for publication in Metallurgical and Materials Transaction, Ref. No. E-TP-09-826-A (2009).

DOI: 10.1007/s11661-011-0688-x

Google Scholar

[5] A. Korbel, J. Pospiech, W. Bochniak, A. Tarasek, P. Ostachowski, J. Bonarski; New structural and mechanical features of hexagonal materials after room temperature extrusion by KoBo method, submitted for publication in International Journal of Materials Research, Ref. No. MR2214 (2010).

DOI: 10.3139/146.110490

Google Scholar

[6] K. Pieła, W. Bochniak, A. Korbel, P. Ostachowski, L. Błaż, Rudy i Metale Nieżelazne 54 (2009), p.356.

Google Scholar

[7] W. Bochniak, Teoretyczne i praktyczne aspekty plastycznego kształtowania metali. Metoda KoBo. Wydawnictwa AGH, Kraków (2009).

Google Scholar

[8] W. Bochniak, A. Brzostowicz, Modern Technologies And Advanced Materials And Products In Sustainable Development of Non-Ferrous Metals Industry, Institute Of Non-Ferrous Metals, Gliwice 2010, p.335.

Google Scholar

[9] M. Victoria, N. Baluc, C. Bailat, Y. Dai, M. Luppo, R. Shaublin, B. Singh, J. Nucl. Mater., 276 (2002), p.114.

Google Scholar

[10] K. Farrel, T. Byun, N. Hashimoto, Mapping flow localization processes in deformation of irradiated reactor structural alloys – final report. Nuclear Energy Research (2002).

DOI: 10.2172/885795

Google Scholar